Sevoflurane enhances ethanol-induced cardiac preconditioning through modulation of protein kinase C, mitochondrial KATP channels, and nitric oxide synthase, in guinea pig hearts.

BACKGROUND: Volatile anesthetics and regular ethanol consumption induce cardioprotection mimicking ischemic preconditioning. We investigated whether sevoflurane enhances ethanol preconditioning and whether inhibition of protein kinase C (PKC) and mitochondrial K(ATP) channels attenuated this enhanced cardioprotection. The effects of regular ethanol consumption on expression of inducible (iNOS) and endothelial (eNOS) nitric oxide synthase were determined. METHODS: Isolated perfused guinea pig hearts underwent 30-min global ischemia and 120-min reperfusion (Control: CTL). The ethanol group (EtOH) received 2.5% ethanol in their drinking water for 6 wk. Anesthetic preconditioning was elicited by 10-min exposure to sevoflurane (1 minimum alveolar anesthetic concentration; 2%) in ethanol (EtOH + SEVO) or nonethanol (SEVO) hearts. PKC and mitochondrial K(ATP) channels were inhibited with chelerythrine and 5-hydroxydecanoate pretreatment, respectively. Contractile recovery was assessed by monitoring of left ventricular developed and end-diastolic pressures. Infarct size was determined by triphenyltetrazolium chloride staining. Expression of iNOS and eNOS were determined by Western blot analysis. RESULTS: After ischemia-reperfusion, hearts from the EtOH, sevoflurane (SEVO), and EtOH + SEVO groups had higher left ventricular developed pressure and lower left ventricular end-diastolic pressure compared with CTL. Infarct size was reduced in EtOH and SEVO hearts compared with CTL (27% and 23% vs 45%, respectively, P \u3c 0.001). Sevoflurane further reduced infarct size in EtOH hearts (27% vs 15%, P \u3c 0.001). Chelerythrine and 5-hydroxydecanoate abolished cardioprotection in both SEVO and EtOH cardioprotected hearts. iNOS expression was reduced and eNOS expression was increased in EtOH hearts. CONCLUSIONS: Sevoflurane enhances cardiac preconditioning induced by regular EtOH consumption. This effect is mediated in part by modulation of PKC and mitochondrial K(ATP) channels, and possibly by altered modulation of NOS expression

P-wave tomography of the mantle beneath the South Pacific Superswell revealed by joint ocean floor and islands broadband seismic experiments

International audienceThree-dimensional P-wave velocity structure of the mantle beneath the South Pacific Superswell is determined through passive broadband seismic experiments on the ocean floor and islands between 2003 and 2005. We collected approximately 1500 relative times of long-period teleseismic P-waves by using a waveform cross-correlation. We analyzed this data set with relative time tomography to depths of 2000 km. The resultant structure shows lateral heterogeneity of approximately +/- 2%, in which a distinct low velocity region is found beneath the center of the Superswell at a depth of 1600 km. At 1200km depth, an elongated low velocity region is found beneath the Society to Pitcairn hotspots. At 800 km depth, two linear low velocity regions are located beneath Tuamotu and Austral islands. Isolated low velocity regions are identified beneath the Society, Marquesas, and Macdonald hotspots at 400 km depth. Our new tomographic images reveal that the large low velocity region rooted in the deep lower mantle is split into two sheets at 1200 km depth and these terminate at approximately 800 km depth. This feature appears to be consistent with the characteristics of a thermo-chemical pile or dome

Acute memory phase of sevoflurane preconditioning is associated with sustained translocation of protein kinase C-alpha and epsilon, but not delta, in isolated guinea pig hearts.

BACKGROUND AND OBJECTIVE: Anaesthetic preconditioning (APC) exerts cardioprotective effects by reducing infarct size and improving recovery of contractile function after ischaemia-reperfusion. The interval between brief exposure to volatile anaesthetic and sustained ischaemia, the acute memory phase, is dependent on intracellular signalling mediating this cardioprotection. Intramyocyte translocation of protein kinase C (PKC) is known to be a key mediator in APC. We examined the relationship between the time frame of the acute memory phase of sevoflurane preconditioning and intramyocyte translocation of PKC-alpha, delta and epsilon to the particulate fraction. METHODS: Isolated perfused guinea pig hearts were subjected to 30 min ischaemia and 120 min reperfusion. APC was elicited with one minimum alveolar concentration sevoflurane for 10 min. Washout times of 10, 30, 60 and 90 min were studied. Contractile recovery was assessed by monitoring left ventricular developed pressures. Infarct size was determined by triphenyltetrazolium chloride staining. Translocation of PKC was examined by western blot analysis. RESULTS: After ischaemia-reperfusion, left ventricular developed pressure recovered to a greater degree with APC compared with control for washout times of 10 and 30 min, but not 60 and 90 min. Similarly, infarct size was reduced for washout times of 10 and 30 min, but not 60 and 90 min. Sustained translocation of PKC-alpha and epsilon, but not delta, was associated with the time frame of the acute memory phase. CONCLUSION: The acute memory phase of sevoflurane preconditioning is limited to less than 60 min. Sustained translocation of PKC-alpha and epsilon, but not delta, correlates with this acute memory phase of sevoflurane preconditioning

Laser-chemical vapor deposition of W Schottky contacts on GaAs\ud using WF6 and SiH4

Reports on the deposition of tungsten on gallium arsenide (GaAs) using a low-temperature laser-chemical vapor deposition process. Induction of metallic W formation from a gas mixture; Columnar structure shown by scanning electron microscopy of the W films; Schottky diodes obtained during a laser based resistless projection patterning process on GaAs

Fabrication of surface nanoscale axial photonics structures with a femtosecond laser

Surface nanoscale axial photonics (SNAP) structures are fabricated with a femtosecond laser for the first time, to the best of our knowledge. The inscriptions introduced by the laser pressurize the fiber and cause its nanoscale effective radius variation. We demonstrate the subangstrom precise fabrication of individual and coupled SNAP microresonators having the effective radius variation of several nanometers. Our results pave the way to a novel ultraprecise SNAP fabrication technology based on the femtosecond laser inscription

Net Charge Fluctuations in Au + Au Interactions at sqrt(s_NN) = 130 GeV

Data from Au + Au interactions at sqrt(s_NN) = 130 GeV, obtained with the PHENIX detector at RHIC, are used to investigate local net charge fluctuations among particles produced near mid-rapidity. According to recent suggestions, such fluctuations may carry information from the Quark Gluon Plasma. This analysis shows that the fluctuations are dominated by a stochastic distribution of particles, but are also sensitive to other effects, like global charge conservation and resonance decays.Comment: 6 pages, RevTeX 3, 3 figures, 307 authors, submitted to Phys. Rev. Lett. on 21 March, 2002. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (will be made) publicly available at http://www.phenix.bnl.gov/phenix/WWW/run/phenix/papers.htm

Event-by-event fluctuations in Mean pTp_T and Mean eTe_T in sqrt(s_NN) = 130 GeV Au+Au Collisions

Distributions of event-by-event fluctuations of the mean transverse momentum and mean transverse energy near mid-rapidity have been measured in Au+Au collisions at sqrt(s_NN) = 130 GeV at RHIC. By comparing the distributions to what is expected for statistically independent particle emission, the magnitude of non-statistical fluctuations in mean transverse momentum is determined to be consistent with zero. Also, no significant non-random fluctuations in mean transverse energy are observed. By constructing a fluctuation model with two event classes that preserve the mean and variance of the semi-inclusive p_T or e_T spectra, we exclude a region of fluctuations in sqrt(s_NN) = 130 GeV Au+Au collisions.Comment: 10 pages, RevTeX 3, 7 figures, 4 tables, 307 authors, submitted to Phys. Rev. C on 22 March 2002. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (will be made) publicly available at http://www.phenix.bnl.gov/phenix/WWW/run/phenix/papers.htm

Flow Measurements via Two-particle Azimuthal Correlations in Au + Au Collisions at sqrt(s_NN) = 130 GeV

Two particle azimuthal correlation functions are presented for charged hadrons produced in Au + Au collisions at RHIC sqrt(s_NN) = 130 GeV. The measurements permit determination of elliptic flow without event-by-event estimation of the reaction plane. The extracted elliptic flow values v_2 show significant sensitivity to both the collision centrality and the transverse momenta of emitted hadrons, suggesting rapid thermalization and relatively strong velocity fields. When scaled by the eccentricity of the collision zone, epsilon, the scaled elliptic flow shows little or no dependence on centrality for charged hadrons with relatively low p_T. A breakdown of this epsilon scaling is observed for charged hadrons with p_T > 1.0 GeV/c for the most central collisions.Comment: 6 pages, RevTeX 3, 4 figures, 307 authors, submitted to Phys. Rev. Lett. on 11 April 2002. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (will be made) publicly available at http://www.phenix.bnl.gov/phenix/WWW/run/phenix/papers.htm